As an associated system that distributes video contents or audio contents, for example, a system that is disclosed in Patent Document 1 is known. A block diagram illustrating an image quality analyzing method and an image quality analyzing apparatus that are disclosed in the same document is shown in FIG. 5.
Both the server side and the client side calculate feature amounts called quality parameters from video, compare the feature amounts, and evaluate the feature amounts, thereby measuring a quality to be perceived by a user.
A video content distributing system that is disclosed in Patent Document 2 is shown in FIG. 6. The video content distributing system includes a video distributing server 600 that distributes video contents, a client 700 that reproduces the video contents from the video distributing server 600, and a network 300 that connects the video distributing server 600 and the client 700 to each other. The network 300 may be an optical network, the Internet or a telephone network.
The video distributing server 600 includes a content accumulation unit 601 that accumulates video contents, an evaluation object determination unit 602 that determines video contents becoming quality evaluation objects, an evaluation position determination unit 603 that determines the positions of the quality evaluation objects among the video contents, a quality parameter calculation unit 604 that calculates a first quality parameter with respect to the positions of the quality evaluation objects among the video contents, a video content distributing unit 605 that executes processing to distribute the video contents to the client 700, a quality parameter receiving unit 606 that receives a second quality parameter calculated in the client 700, a quality evaluating unit 607 that compares the first quality parameter and the second quality parameter (calculates the difference of the first and second quality parameters) and calculates a quality evaluation parameter according to whether the difference is within an allowable value, and a usage unit 608 that executes predetermined processing based on the quality evaluation parameter. The video content distributing unit 605 executes digital watermark processing for inserting digital watermarks into the video contents or encoding processing for encoding the video contents.
The client 700 includes a video content receiving unit 701 that receives the video contents from the video distributing server 600, an evaluation object determination unit 702 that inputs the video contents including distribution destination information and distribution periods thereof, selects contents matched with the input contents from a database (not shown in the drawings), and determines the selected contents as video contents of evaluation objects, an evaluation position determination unit 703 that determines the positions of the evaluation objects among the video contents of the evaluation objects, based on at least one of a specific frame of an image frame and a pixel region of one frame, a quality parameter calculation unit 704 that calculates a second quality parameter from the video contents, and a quality parameter transmitting unit 705 that transmits the calculated second quality parameter to the video distributing server 600.
As examples of a method that determines the positions of the evaluation objects, a method that inputs the frame positions and the region positions of frame contents from the user side and a method that regards only regions where the motion compensation data amount calculated by encoding processing from the video contents is more than a predetermined threshold value as partial frames having motions and extracts the regions as the evaluation objects, which are simplest methods, are used. As another example of the method, processing for calculating a motion vector extended between video frames and determining regions where the magnitude is equal to or more than a threshold value as the positions of the evaluation objects is used.
A transmission quality deterioration adding apparatus 810 that is disclosed in Patent Document 3 is shown in FIG. 7. The transmission quality deterioration adding apparatus based on the associated technology is connected to a packet network 820 together with a counterpart terminal 830, and a situation where a packet stream including transmission quality deterioration transmitted from the transmission quality deterioration adding apparatus 810 is received in the counterpart terminal 830 and a situation where the counterpart terminal 830 transmits transmission quality information in a receiving terminal 831 to the transmission quality deterioration adding apparatus 810 are shown.
As an embodiment of a terminal that can monitor the transmission quality in the receiving terminal 831 and transmit a monitoring result as the transmission quality information, a terminal that mounts a RTCP XR protocol is known.    [Patent Document 1] Japanese Laid-open patent publication NO. 2000-92522    [Patent Document 2] Japanese Laid-open patent publication NO. 2003-319420    [Patent Document 3] Japanese Laid-open patent publication NO. 2005-30345